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Welcome to the web sites of the Center for Materials Research

The Center for Materials research is a core-facility of JLU and supported by the departments of chemistry and physics.
It serves for running joint research projects, for the coordination of study programs in materials science and for promoting the qualification of doctoral candidates.
The Center regularly organizes events covering recent issues of materials research. It also offers central experimental resources to its member research groups.
Please find additional information in "About us".

Comment on Website Problems due to Conversion to Plone 6

Recent notice for the users of the ZfM websites
Our websites are currently being converted to a new system (CMS). Temporarily there may be broken links and missing page content. We are working on solutions and ask for your patience.

November

Picture of the Month - November 2022

Omnidirectional Light-Tunable Broadband Terahertz-Wave Hybrid Antireflection Coating Composed of PEDOT:PSS and Graphene on Silicon

The demonstration of an actively configurable broadband terahertz (THz) antireflection (AR) coating supports the achievement of high-performance and versatile THz components. Here, we explore an AR coating based on an impedance matching method employing a composite film structure made of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) on graphene placed on a silicon substrate which can be driven by near-infrared light. Omnidirectional broadband properties of such active AR coating can be efficiently achieved by charge-carrier-density-tunability via optical irradiance of less than 0.27 W·cm–2, with which suppression of THz-wave reflection is demonstrated for incidence angles from 0 to 70°, concerning the broadband frequency range of 0.1–3.0 THz. In addition, the composite film features an ultrafast response time of ∼5 ps. Furthermore, our recent joint study within the Sino-German FNMS-COOP group’s frame, involving scientists from Hefei, Hangzhou and Gießen, shows that the active AR coating can improve the performance of a reflectance-tunable THz-wave polarization reflector by the elimination of Fabry–Pérot interference (https://doi.org/10.1021/acsami.2c10186). By investigating the NIR-irradiance dependence of the hybrid system’s active AR mechanism, the essential role of the PEDOT:PSS/graphene layers in promoting the charge separation at the interface and therefore changing the photoconductivity of the composite film to achieve impedance matching under optical excitation is highlighted.

This picture was submitted by Dr. Arash Rahimi-Iman (with Gen Liu und Weien Lai).

Further insights into the research activities of the ZfM groups can be found in the Gallery.

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Bericht 2020-2021